Profiling interfacial reaction features between diamond and Cu-Sn-Ti active filler metal brazed at 1223 K

Diamond/Cu-Sn-Ti composites have been successfully prepared by cold-press forming in conjunction with high-temperature vacuum active brazing at 1223 K.Ensuing wetting behaviors between diamond and filler metal,interfacial characteristics of the reaction layer,and wear resistance of the bulky composite have been fully investigated.It is revealed that all diamond particles can only be fully coated when the TiH_(2)content exceeds 5 wt%,below which sharp edges on diamond can still be observed.The interfacial reaction layer is found to be composed of TiC,the thickness of which is demonstrated to increase as a function of TiH_(2)content,arriving at the peak value of 1.70μm and remaining almost constant afterwards.It is further shown that the maximum wear resistance occurs approaching 5 wt%TiH_(2)content.Potential mechanisms responsible for such interesting phenomena have been postulated.

Measuring County Resilience After the 2008 Wenchuan Earthquake

The catastrophic earthquake that struck Sichuan Province,China,in 2008 caused serious damage to Wenchuan County and surrounding areas in southwestern China.In recent years,great attention has been paid to the resilience of the affected area.This study applied the resilience inference measurement(RIM) model to quantify and validate the community resilience of 105 counties in the impacted area.The RIM model uses cluster analysis to classify counties into four resilience levels according to the exposure,damage,and recovery conditions.The model then applies discriminant analysis to quantify the influence of socioeconomic characteristics on the county's resilience.Analysis results show that counties located at the epicenter had the lowest resilience,but counties immediately adjacent to the epicenter had the highest resilience capacities.Counties that were farther away from the epicenter returned to normal resiliency quickly.Socioeconomic variables—including sex ratio,per capita GDP,percent of ethnic minority,and medical facilities—were identified as the most influential characteristics influencing resilience.This study provides useful information to improve county resilience to earthquakes and support decision making for sustainable development.

Pharmacodynamics simulation of HOEC by a computational model of arachidonic acid metabolic network

Backgrounds Arachidonic acid (AA) metabolic network is activated in the most inflammatory related diseases, and small-molecular drugs targeting AA network are increasingly available. However, side effects of above mentioned drugs have always been the biggest obstacle.什)-2-( 1 -hydroxy 1-4-oxocycIohexyl) ethyl caffeate (HOEC), a natural product acted as an inhibitor of 5-Iipoxygenase (5-LOX) and 15-LOX in vitro^ exhibited weaker therapeutic effect in high dose than that in low dose to collagen induced arthritis (CIA) rats. In this study, we tried to elucidate the potential regulatory mechanism by using quantitative pharmacology. Methods: First, we generated an experimental data set by monitoring the dynamics of AA metabolites, concentration in A23187 stimulated and different doses of HOEC co-incubated RAW264.7. Then we constructed a dynamic model of A23187-stimulated AA metabolic model to evaluate how a model-based simulation of AA metabolic data assists to find the most suitable treatment dose by predicting the pharmacodynamics of HOEC? Results: Compared to the experimental data, the model could simulate the inhibitory effect of HOEC on 5-LOX and 15-LOX, and reproduced the increase of the metabolic flux in the cyclooxygenase (COX) pathway. However, a concomitant, early-stage of stimulation-related decrease of prostaglandins (PGs) production in HOEC incubated RAW264.7 cells was not simulated in the model. Conclusion-. Using the model, we predict that higher dose of HOEC disrupts the flux balance in COX and LOX of the AA network, and increased COX flux can interfere the curative effects of LOX inhibitor on resolution of inflammation which is crucial for the efficient and safe drug design.

Extraordinary toughening enhancement in nonstoichiometric vanadium carbide

1.Introduction Fracture toughness is the ability of materials against both the initiation and propagation of cracks[1],which is a crucial mechanical property for safety-critical applications of structural materials.Although the yield strength of ceramics is significantly higher than that of metallic materials,the fracture toughness is severely lower than that of metallic materials due to the strongly directional covalent bonding[1-3].For a long time,how to improve the fracture toughness of ceramics without the deterioration of strength(or hardness)has been one of the most challenging problems in materials science.